String template filler

Template filling replaces placeholders such as {{name}} in a text with values from a data object. It is how personalised emails, notification messages, configuration files and documents are generated from one template. This tool lets you test a template against JSON data instantly, without writing code.

How to use it

1. Write or paste a template with placeholders in double curly braces.
2. Provide the data as JSON, with keys matching the placeholder names.
3. Copy the filled result.

Example

Template:

Hi {{name}}, your order #{{order.id}} of {{order.total}} has shipped to {{city}}.

Data (as JSON with double quotes):

{ name: 'Asha', city: 'Pune', order: { id: 1042, total: '₹2,499' } }

Result: Hi Asha, your order #1042 of ₹2,499 has shipped to Pune. Dot notation such as order.id reads nested values.

Things to watch

• Missing keys: a placeholder without data is left empty or unchanged, depending on the setting. Always check the output for gaps such as Hi ,.
• Exact names: placeholders are case-sensitive; {{Name}} and {{name}} are different.
• Escaping: when the result is used as HTML, user-supplied values must be HTML-escaped to prevent injection. Template engines like Mustache and Handlebars escape by default with double braces.

In code

Mustache, Handlebars, Jinja2 (Python), Liquid (Shopify) and Go's text/template use similar syntax with extra features such as loops and conditionals. Use this tool for quick previews and simple substitutions.